1) Field of the Invention
The present invention relates to an electrical connecting arrangement for establishing electrical connections of electronic printed-circuit boards which are inserted into and taken out of a cabinet, a housing or the like.
2) Description of the Related Art
Electronic printed-circuit boards are often detachably mounted in an electronic installation such as a digital transmission apparatus, a main frame computer or the like. Such an electronic installation comprises a plurality of rack sections, each of which includes a top wall portion, and a bottom wall portion. To detachably mount the printed-circuit board in the rack section, the respective top and bottom wall portions are provided with a plurality of upper guide rails arranged at regular intervals and a plurality of lower guide rails arranged at regular intervals, with the upper and lower guide rails being aligned with each other, respectively, and being oriented in a direction in which the printed-circuit boards are inserted into and taken out of the rack section. In particular, the aligned upper and lower guide rails are arranged and constituted so as to be slidably engaged with respective upper and lower edges of an electronic printed-circuit board, whereby the printed-circuit board can be inserted into and taken out of the rack section along the aligned upper and lower guide rails. Of course, the detachable mount of the printed-circuit board is directed to ease of maintenance of the electronic installation.
Each of the rack sections is provided with a rear wall portion, a so called "backplane", for establishing electrical connections of the printed-circuit boards inserted into the rack section in place. Namely, each of the printed-circuit boards is electrically connected to other printed-circuit boards or an outside electronic installation through the intermediary of the backplane, so that input and/or output signals can be interchanged thereamong. Conventionally, it is necessary to use at least two connectors: an inner connector and outer connector, for one printed-circuit board, for the establishment of the electrical connection thereof. In particular, the inner connector includes two inner connector halves which can be coupled to each other: a first inner connector half is attached to a rear or back side of the printed-circuit board; and the other or second inner connector half is attached to an inner wall surface of the backplane. When the printed-circuit board is inserted in place into the rack section, a complete electrical couple of the inner connector halves is achieved. On the other hand, the outer connector also includes two outer connector halves which can be coupled to each other: a first outer connector half is attached to an outer wall surface of the backplane; and the other or second outer connector half is joined to an end of a cable extended from an outside electronic installation or another electronic printed-circuit board mounted in the electronic installation concerned. The second inner connector half is electrically connected to the first outer connector half through wiring provided in the backplane.
As mentioned above, the conventional arrangement necessarily involves at least two inner and outer connectors for one printed-circuit board for establishing the electrical connection thereof. This means that a large number of connectors is necessary for the establishment of electrical connections of all of the printed-circuit boards mounted in the electronic installation.